fix: complete InvesteMoz validation and error corrections

app/Support/CheckedFile.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace App\Support;
+
+use RuntimeException;
+
+/** Required evidence must be readable; an I/O failure is never empty content or a matching hash. */
+final class CheckedFile
+{
+    /** @phpstan-impure */
+    public static function read(string $path): string
+    {
+        $bytes = @file_get_contents($path);
+        if ($bytes === false) {
+            throw new RuntimeException('Required file could not be read.');
+        }
+
+        return $bytes;
+    }
+
+    /** @phpstan-impure */
+    public static function sha256(string $path): string
+    {
+        $hash = @hash_file('sha256', $path);
+        if ($hash === false) {
+            throw new RuntimeException('Required file integrity could not be verified.');
+        }
+
+        return $hash;
+    }
+
+    /** @phpstan-impure */
+    public static function size(string $path): int
+    {
+        $size = @filesize($path);
+        if ($size === false) {
+            throw new RuntimeException('Required file size could not be verified.');
+        }
+
+        return $size;
+    }
+
+    /** @phpstan-impure */
+    public static function matches(string $path, string $expected): bool
+    {
+        return hash_equals($expected, self::sha256($path));
+    }
+}